1. Industrial Field of the Invention
The present invention relates to an improvement for preventing the emission of fuel vapor generated during fuel supply.
2. Description of the Prior Art
Japanese Utility Model Unexamined Publication No. 59-40561 discloses a proposal for improving the absorption and desorption efficiency of fuel vapor by defining a restriction hole in an atmospheric air port of a canister.
Further, Japanese Utility Model Unexamined Publication No. 62-38467 discloses an apparatus for preventing the emission of fuel vapor in which fuel vapor generated during fuel supply is to be absorbed in a canister and the absorbed fuel vapor is to be desorbed by means of an intake air caused by an engine operation. In this apparatus, a restriction hole is not defined in an atmospheric air port of the canister.